Hasenhuttl also revealed that new signing Mohammed Salisu is still working towards reaching full match fitness having been left out of the 1-0 defeat to Crystal Palace on Saturday.
When asked when fans can expect to see Salisu in action, Hasenhttul said: "It's difficult to say. We know that he's got some issues and it'll take some time but he's working with the physios so let's have a look at when he's back.
On bringing in reinforcements, the Austrian added: "The market is open and we know that we lost a No 6. We need alternatives and we can be sure that we're looking for one.
"We know our limits but we'll have a look. We know our squad is not the biggest one and we have a lot of young players in our squad but we do need alternatives in some positions."
When asked about the future of Sofiane Boufal, who was omitted from the match-day squad, Hasenhttul said: "We have one or two players who could move on and Sofiane is one of them."